On the coast of Chile, bird nests show the scars of plastic pollution

SANTIAGO, Chile — The red-legged cormorants that make their nests along the coast of the Atacama Desert in northern Chile normally use a mixture of seaweed, feathers and guano to build their homes.

But in a pinch, they'll use whatever is available. And in Mejillones Bay, a busy port town, plastic waste is plentiful.

“This could be the most contaminated nesting colony in the world,” said Ana García-Cegarra, a professor of biology at the University of Santo Tomás Antofagasta.

The cormorant colony is the subject of a new paper published in the peer-reviewed journal Marine Pollution Bulletin, which García-Cegarra is an author of and was produced in conjunction with the nonprofit Marine Fauna and Whale-Watching Center. It found that every bird nest contained some plastic.

“Other studies have found maybe 80 percent of nests in a colony had some plastic content, but all 100 percent of the 151 nests we counted contained plastic," García-Cegarra said.

Photos taken by researchers show how the red-legged cormorants used plastic shopping bags, nylon fishing tackle and strips of sand bags from industrial works when building nests for their young.

The study — and photos — offer a striking look at how plastic pollution has hammered ocean and coastal ecosystems. Though plastics have been widely used by humans for 70 years, their devastating environmental impacts are only just starting to be understood.

“It’s only really in the last five years or so that we have seen a surge in studies revealing the true scale of the amount of plastic contamination on our planet, with most of its detrimental effects reported in our oceans,” said Mauricio Urbino, a zoologist at Chile’s University of Concepcion. “The worrying thing is that, if we don’t reduce plastic use now, it is only going to get worse.”

García-Cegarra said that the plastics are dangerous to birds, and that they had found many dead cormorants in nests while assessing them. The two main threats were birds becoming entangled and starving or suffocating when they were unable to free themselves, or when they ingested the plastics.

"As these birds are divers, they probably collect the plastics from the seabed and transfer them to their nests,” García-Cegarra said. ”Swallowing the plastics, as they sometimes do, might kill them. Equally, they might transfer them to their chicks or accumulate toxins in their organs.”

One third of the plastics from the nests analyzed by García-Cegarra's team were plastic shopping bags, which Chile banned in 2018 for large supermarkets, but the use of which still continues among small retailers. About 35 percent of the plastics were from maxi sand bags used by some of the bay’s port industries as wave breakers, while 15 percent of the nest plastics was fishing gear.

Due to the bay’s calm waters, nine large port terminals have been installed since 2003, serving local mines for lead, carbon, lithium, oil and copper. While cormorants normally choose cliffs and caves for their nests, underhangs on the piers at three of the terminals were chosen by cormorants as nesting sites.

“After nearly 20 years of heavy industry and bad control over single-use plastics like shopping bags in the town, there is probably now more plastic than seaweed available to the birds,” García-Cegarra said.

Yacqueline Montecinos, a marine conservation officer at the World Wildlife Fund Chile, said that the impacts of plastics on marine fauna are intensifying every year and that the results of the study were unsurprising.

“What you are seeing with these cormorants is sadly something that’s happening in every part of the ocean, and a threat to all species of marine fauna,” she said.

Montecinos also warned that the Great Pacific Garbage Patch, a colossal island of plastic waste estimated to be the size of Mexico, sometimes circulates on currents close to Chile’s coast and the site of the birds’ colony.

“We have seen contamination in other animals close to this phenomenon,” she said. “It could be adding to the volume of plastics in the birds’ environment.”

The Antofagasta region, where the bay sits, is one of Chile’s wealthiest due to the high amount of extractive industries. Mejillones, around 40 miles north of the regional capital, also named Antofagasta, was historically a small fishing town that started to boom in the 1800s after nearby guano deposits were exploited, with the nine new port terminals now also serving a major gas works and thermo-electric plant.

“Our bad habits in the consumption of plastic are affecting all marine fauna, now reaching bird nests, abyssal pits in the depths of the ocean and even to our table due to the fish or mussels that ingest it,” García-Cegarra said.

“We must act now and reduce our plastic consumption.”